JPS601431Y2 - object detection device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an object detection device that detects the presence or absence of a sheet-like object, and more specifically, the present invention relates to an object detection device that detects the presence or absence of a sheet-like object. The present invention relates to an object detection device that detects the presence or absence of the object.

Generally, in paper machines for producing newspapers, high-quality paper, kraft paper, etc., the measurement of moisture content is an important measurement and is continuously carried out using an infrared analyzer that uses near-infrared rays.

FIG. 1 is a configuration explanatory diagram showing the detection head of such an infrared analyzer. In the figure, 1 is the upper head of the detection section, 2 is the lower detection head, 3 is the object to be measured, and 4 is the near-infrared irradiation section. ,
5 is a near-infrared light receiving part, 6a and 6b are light projecting parts of the detection device,
? a and 7b are the light receiving parts of the detection device, and 8a and 8b are the light projecting parts 6.
It is irradiated from the objects 3a and 6b and reflected by the light receiving part 7a.
, 7b, and 9 are near-infrared rays emitted from the irradiation section 4, transmitted through the object to be measured 3, or scattered by the surfaces of the object to be measured 3 and the upper and lower heads, and reaching the light receiving section 5.

In the infrared analyzer having the above configuration, the object to be measured 3 runs in a direction perpendicular to the plane of the paper of FIG. It operates in the left and right directions on the paper of FIG.

Moreover, the light beam 8at irradiated from the light projecting section 6ay6b
8b detects the presence or absence of the object to be measured 3, and supplies an information signal to the infrared analyzer.

FIG. 2 is an explanatory diagram of the configuration of a conventional detection device, and in the figure,
10 is a light emitter, 11 is a light receiver, 12 is a light emitting/receiving window, and 13 is a shielding plate.

Hereinafter, in FIGS. 2 to 6, the same symbols as in FIG. 1 have the same meanings, and the explanations in each figure will be omitted.

Conventional detection device with the above configuration (hereinafter referred to as “Conventional Example (1)”)
), the light beam 8 emitted from the floodlight 10
a passes through the light emitting window 12 and is reflected by the object to be measured 3, and is reflected at the light receiving window 1.
2 and reaches the photoreceiver 11 where it is detected.

However, if powdery matter (paper powder when the measured object 3 is paper) falls and adheres to the light emitting/receiving window 12 from the measured object 3,
As shown in FIG. 3, the light beam 14 emitted from the light emitter 10 passes through the light emitting window 12, is reflected by the powdery material 17, passes through the light receiving window 12, reaches the light receiver 11, and is detected. 3 is detected as being present even when it is not present, and it has the drawback of providing a false information signal to the infrared analyzer.

FIG. 4 is an explanatory diagram of the configuration of another conventional example (hereinafter referred to as 1 conventional example (2)) of the above-mentioned detection device, and in the figure, 13 is a shielding plate that reaches the surface of the light emitting/receiving window. .

In the conventional example (2) having the above configuration, the light emitting/receiving window 12
Even if a powdery substance adheres to the surface of the light beam 8a, unlike the case of the conventional example (1), the light beam 8a reflected by the powdery substance is blocked by the shielding plate and does not enter the light receiver 11. The presence or absence of the object to be measured 3 will not be detected erroneously.

However, when the object to be measured 3 is located very close to the light emitting/receiving window 12 in FIG. 11, and even if the object to be measured 3 exists, it cannot be detected.

The present invention was devised in view of these drawbacks, and its purpose is to prevent the measurement object located very close to the light emitting/receiving window from being mistaken even by powdery substances accumulated on the surface of the light emitting/receiving window. An object of the present invention is to provide an object detection device that can accurately detect even the body.

The feature of this invention is that an object detection device that detects the presence or absence of a sheet-like object uses a light shielding plate whose tip reaches the light-receiving part to the boundary surface of the light-receiving part and whose tip is significantly thinner than the bottom. That's what happened.

Hereinafter, the present invention will be explained in detail using figures.

FIG. 5 is a configuration explanatory diagram showing an embodiment of the present invention,
In the figure, reference numeral 15 denotes a thin shielding plate which is integrally connected to the upper part of the shielding plate 13 and is clamped between a light receiving window and a light projecting window.

Furthermore, the light beam 8a emitted from the floodlight 10 is transmitted through the light emission window 1.
2, is reflected by the object to be measured 3, passes through the light receiving window 12, and reaches the light receiver 11.

According to one embodiment of the present invention having the above configuration, the object to be measured 3
Even when the light emitting and receiving window 12 is located very close to the light emitting/receiving window 12, since the shielding plate 15 is thin, the reflected light rays enter the light receiver 11 without being protected from the optical path by the thickness of the shielding plate 15, and the object to be measured 3 can be detected accurately.

In addition, since the shielding plate 5 reaches the surface of the light emitting/receiving window 12, the reflected light due to powdery substances accumulated on the surface of the light emitting/receiving window 12 cannot enter the light receiver, and it is possible to detect whether the object to be measured 3 is present or not. There is no possibility of false detection.

Note that the shielding plate 15 according to the present invention is not limited to the above-mentioned embodiment, and the shielding plate clamped to the light receiving part and the light projecting part reaches the surface of the light projecting and receiving window 12, and Floodlight 1
Various modifications are possible within the scope of the configuration in which the light rays irradiated from zero and reflected by the object to be measured 3 can reach the receiver without any interference along the optical path.For example, the configuration shown in FIG. 6 is possible. be.

In FIG. 6, reference numeral 16 denotes a shielding plate of another embodiment of the detection device according to the present invention, which has an isosceles triangular cross section.

In the figure, after passing through the light projection window 12, the light beam 8a emitted from the projector 10 passes through the light receiving window 12 and reaches the light receiver 11 without having its optical path blocked by the thickness of the reflective shielding plate 16 at the object to be measured 3. reached and detected.

Furthermore, since the shielding plate 16 reaches the surface of the light emitting/receiving window 12, the presence or absence of the object to be measured 3 will not be erroneously detected due to powdery matter accumulated on the surface of the light emitting/receiving window 12.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an infrared analyzer equipped with a detection device, Figs. 2 to 4 are explanatory diagrams of the configuration of a conventional detection device, and Figs. 5 and 6 are illustrations of an embodiment of the present invention. FIG. DESCRIPTION OF SYMBOLS 1...Detection part upper head, 2...Detection lower head, 3...Measurement object, 6a, 6b...
...The light emitting part of the detection device? a, 7b... Light receiving part of the detection device, 8°14... Light beam, 10...
...Emitter, 11...Receiver, 12...
...Light projection/reception window, 13.15 and 16... Shielding plate.

Claims (1)

[Scope of utility model registration request] The upper head has an irradiation section that irradiates near-infrared rays onto a sheet-shaped object to be measured, and the lower head has a light-receiving section that receives near-infrared rays that have passed through the object. In an object detection device that is attached to an infrared analyzer that measures the amount of water in a measurement object and detects the presence or absence of the measurement object using light, the object detection device includes a floodlight that irradiates the measurement object with light; a light projecting part having a light projecting window; a light receiving part having a light receiving window therein and including a light receiver for sensing reflected light from the object to be measured; and a light sandwiched between the light receiving part and the light projecting part. A shielding plate is provided at an end of the lower head so that the light emitting part and the light receiving part are adjacent to each other with the shielding plate interposed therebetween, and the light shielding plate has a tip that is connected to the light emitting part and the light receiving part. An object detection device characterized in that the thickness of the tip reaches the surface of the boundary between the parts and the thickness of the tip is significantly thinner than the thickness of the bottom part.